What are different kinds of trig identities?
1. If sin x = -1/3, what is cosx?
2. Simplify the expression (sinx + cosx)^2 + (sinx - cosx)^2
3. Verify the identity cotx - tanx = (csc2x - sec2x)/sinxcosx
1. sin2x + cos2x = 1
2. tan2x + 1 = sec2x
3. 1 + cot2x = csc2x
1. cscx = 1/sinx
2. secx = 1/cosx
3. cotx = 1/tanx
The Tangent and Cotangent Identities
1. tanx = sinx/cosx
2. cotx = cosx/sinx
Identities for Negatives
1. sin(-x) = -sinx (the sine function is an odd function)
2. cos(-x) = cosx (the cosine function is an even ...
This posting lists trigonometric identities and gives examples of different types of problems that make use of them.